package com.pay.payment.service.impl;

import com.pay.common.result.Result;
import com.pay.payment.dto.PaymentRequest;
import com.pay.payment.dto.PaymentResponse;
import com.pay.payment.service.PaymentService;
import lombok.extern.slf4j.Slf4j;
import org.apache.dubbo.config.annotation.DubboService;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;

import java.math.BigDecimal;
import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;

@Slf4j
@Service
@DubboService
public class PaymentServiceImpl implements PaymentService {
    
    // 模拟支付记录存储，实际项目中应该使用数据库
    private static final Map<String, PaymentResponse> paymentStore = new ConcurrentHashMap<>();
    
    @Override
    @Transactional
    public Result<PaymentResponse> processPayment(PaymentRequest request) {
        log.info("支付受理，请求参数：{}", request);
        
        try {
            // 1. 参数校验
            if (request.getOrderNo() == null || request.getOrderNo().trim().isEmpty()) {
                return Result.error("订单号不能为空");
            }
            if (request.getAmount() == null || request.getAmount().compareTo(BigDecimal.ZERO) <= 0) {
                return Result.error("支付金额不能为空或小于等于0");
            }
            if (request.getChannel() == null || request.getChannel().trim().isEmpty()) {
                return Result.error("支付渠道不能为空");
            }
            
            // 2. 签名验签（这里简化处理，实际应该验证签名）
            if (!verifySignature(request)) {
                return Result.error("签名验证失败");
            }
            
            // 3. 生成支付流水号
            String tradeNo = generateTradeNo();
            
            // 4. 调用渠道适配器进行支付
            PaymentResponse response = new PaymentResponse();
            response.setTradeNo(tradeNo);
            response.setOrderNo(request.getOrderNo());
            response.setAmount(request.getAmount());
            response.setStatus("PENDING");
            response.setPayUrl("/pay/redirect/" + tradeNo);
            response.setMessage("支付处理中");
            
            // 5. 保存支付记录
            paymentStore.put(tradeNo, response);
            
            log.info("支付受理成功，交易号：{}，渠道：{}", tradeNo, request.getChannel());
            
            return Result.success(response);
            
        } catch (Exception e) {
            log.error("支付受理失败", e);
            return Result.error("支付受理失败：" + e.getMessage());
        }
    }
    
    @Override
    @Transactional
    public Result<Void> handleCallback(String channel, String callbackData) {
        log.info("处理回调，渠道：{}，数据：{}", channel, callbackData);
        
        try {
            // 1. 参数校验
            if (channel == null || channel.trim().isEmpty()) {
                return Result.error("渠道不能为空");
            }
            if (callbackData == null || callbackData.trim().isEmpty()) {
                return Result.error("回调数据不能为空");
            }
            
            // 2. 解析回调数据
            CallbackInfo callbackInfo = parseCallbackData(channel, callbackData);
            if (callbackInfo == null) {
                return Result.error("回调数据解析失败");
            }
            
            // 3. 验证回调签名
            if (!verifyCallbackSignature(channel, callbackData)) {
                return Result.error("回调签名验证失败");
            }
            
            // 4. 更新支付状态
            PaymentResponse payment = paymentStore.get(callbackInfo.getTradeNo());
            if (payment != null) {
                payment.setStatus(callbackInfo.getStatus());
                payment.setMessage(callbackInfo.getMessage());
                paymentStore.put(callbackInfo.getTradeNo(), payment);
                
                log.info("支付状态更新成功，交易号：{}，状态：{}", callbackInfo.getTradeNo(), callbackInfo.getStatus());
            }
            
            // 5. 发送支付结果事件（这里简化处理，实际应该发送Kafka消息）
            log.info("支付回调处理成功，交易号：{}", callbackInfo.getTradeNo());
            
            return Result.success();
            
        } catch (Exception e) {
            log.error("处理回调失败", e);
            return Result.error("处理回调失败：" + e.getMessage());
        }
    }
    
    @Override
    @Transactional
    public Result<Void> supplementOrder(String orderNo) {
        log.info("补单处理，订单号：{}", orderNo);
        
        try {
            // 1. 参数校验
            if (orderNo == null || orderNo.trim().isEmpty()) {
                return Result.error("订单号不能为空");
            }
            
            // 2. 查询订单状态
            PaymentResponse payment = findPaymentByOrderNo(orderNo);
            if (payment == null) {
                return Result.error("订单不存在");
            }
            
            // 3. 检查是否需要补单
            if ("SUCCESS".equals(payment.getStatus())) {
                return Result.error("订单已支付成功，无需补单");
            }
            
            // 4. 调用渠道查询接口
            String channelStatus = queryChannelStatus(payment.getTradeNo());
            if (channelStatus != null) {
                payment.setStatus(channelStatus);
                paymentStore.put(payment.getTradeNo(), payment);
                
                log.info("补单成功，订单号：{}，状态：{}", orderNo, channelStatus);
            } else {
                log.info("补单未发现状态变化，订单号：{}", orderNo);
            }
            
            return Result.success();
            
        } catch (Exception e) {
            log.error("补单处理失败", e);
            return Result.error("补单处理失败：" + e.getMessage());
        }
    }
    
    /**
     * 验证签名
     */
    private boolean verifySignature(PaymentRequest request) {
        // 这里简化处理，实际应该验证签名
        // 实际项目中应该根据不同的渠道使用不同的签名算法
        return true;
    }
    
    /**
     * 生成交易号
     */
    private String generateTradeNo() {
        return "PAY" + System.currentTimeMillis() + String.format("%04d", (int)(Math.random() * 10000));
    }
    
    /**
     * 解析回调数据
     */
    private CallbackInfo parseCallbackData(String channel, String callbackData) {
        // 这里简化处理，实际应该根据不同的渠道解析不同的回调数据格式
        try {
            // 模拟解析回调数据
            String[] parts = callbackData.split("\\|");
            if (parts.length >= 3) {
                CallbackInfo info = new CallbackInfo();
                info.setTradeNo(parts[0]);
                info.setStatus(parts[1]);
                info.setMessage(parts[2]);
                return info;
            }
        } catch (Exception e) {
            log.error("解析回调数据失败", e);
        }
        return null;
    }
    
    /**
     * 验证回调签名
     */
    private boolean verifyCallbackSignature(String channel, String callbackData) {
        // 这里简化处理，实际应该验证回调签名
        // 实际项目中应该根据不同的渠道使用不同的签名验证算法
        return true;
    }
    
    /**
     * 根据订单号查找支付记录
     */
    private PaymentResponse findPaymentByOrderNo(String orderNo) {
        return paymentStore.values().stream()
                .filter(payment -> orderNo.equals(payment.getOrderNo()))
                .findFirst()
                .orElse(null);
    }
    
    /**
     * 查询渠道状态
     */
    private String queryChannelStatus(String tradeNo) {
        // 这里简化处理，实际应该调用渠道查询接口
        // 模拟查询渠道状态
        if (tradeNo.startsWith("PAY")) {
            // 模拟70%的概率查询到成功状态
            if (Math.random() < 0.7) {
                return "SUCCESS";
            }
        }
        return null;
    }
    
    /**
     * 回调信息内部类
     */
    private static class CallbackInfo {
        private String tradeNo;
        private String status;
        private String message;
        
        // Getters and Setters
        public String getTradeNo() { return tradeNo; }
        public void setTradeNo(String tradeNo) { this.tradeNo = tradeNo; }
        public String getStatus() { return status; }
        public void setStatus(String status) { this.status = status; }
        public String getMessage() { return message; }
        public void setMessage(String message) { this.message = message; }
    }
}



